How to Use Overlays on the PAXcam Live Preview

How to Use Overlays on the PAXcam
Live Preview
LECO Corporation; Saint Joseph, Michigan USA
Users may overlay a stored reference image on top of
a Live PAXcam image preview, or overlay some
templated text, lines, scale bar or other annotations
on the Live preview as well. These features extend the
usefulness of the PAXcam in measuring, aligning, and
comparing images in analytical processes. Take
advantage of PAXcam's flexibility in performing these
functions, to expand your PAXcam imaging
6. Use the Template Overlay button to access the list of
templates that may be used as overlays, and choose
the appropriate one.
Videotext Templates
Stored videotext templates may now be overlayed on
Live images as well, using the new PAXcam overlay
Basic Sequence for Applying an Overlay
1. Capture an image at the resolution you will be
working at with the PAXcam.
2. Create a videotext template on the image
using the Annotations toolbar in PAX-it.
3. Store the template using the "Save as
Videotext Template" function in PAX-it, and
give it a name. You may store multiple
templates for different uses. It is a good
idea to indicate the size of the template
in its title, if you are creating different templates
for different resolution images (see step #5).
4. Start the PAXcam and adjust your live image for
5. On the 'Advanced' tab in the PAXcam interface,
indicate the size of the template being used. The
template will then be scaled for whatever preview
size you choose. If you commonly switch between
different sized templates, you may wish to have the
software prompt you to specify the template size
each time one is chosen, by checking the
7. You will be asked if you wish to apply the template to
the images that are captured, so that captured images
also have the videotext already on them when they are
put into the PAX-it folder.
8. The template appears over the live preview image.
9. To remove the template from the live view,
press the "Remove Template" button.
Moving the Overlay
Overlays may be moved in any direction by clicking the
mouse on the image and holding it down as you
drag the mouse. The "Move Item" cursor
appears. By releasing the mouse button,
the template will be moved to the new position.
Note: To restore the template to its original "home" position,
you may click the mouse button on the image, then click
the right mouse button while continuing to hold the left
button down.
Overlays may also be rotated on the image. Use the right
mouse button to click on the image. The "Rotate Item"
cursor appears. As the right mouse button is held down
and the mouse is moved, the cursor's orientation changes
to show the effect that the operation will have on the
template (NOTE: the 'top' of the template is noted by the
smaller cross on the cursor). As you release the mouse
button, the template will change its orientation to the new
Top of overlay
is indicated by
Overlay rotation tool
Check this box if your overlay
sizes will vary.
Enter the resolution of the
images you will be using for
PAXcam overlays.
Metallographic Application Note
A standard feature of PAX-it allows users to create
overlays on stored images, with the Annotations
toolbar from the main PAX-it screen. Circles, boxes,
lines, arrows, text, and more may be drawn on a
stored image, and adjusted for size, color, and
placement. Any created annotations overlay may be
stored as a template and recalled, so that multiple
stored images may have the same editable
annotations put on them (see article How to Use
Videotext Templates in PAX-it).
Delivering the Right Results
To restore the template to its original "home" position,
you may click the right mouse button on the image, then
click the left mouse button while continuing to hold the
right button down.
Technical Note: If you use a measurement line or scale
bar as a videotext template, rotating the template may
adjust the measurement by plus or minus one pixel on
either end.
Check this box if
your overlay sizes
will vary.
Enter the resolution of the
images you will be using
for PAXcam overlays.
Uses for the 'Overlay Template' Feature
The overlaying of videotext on the live image is
important to users for a variety of reasons.
1. Place a templated arrow or circle on the image, then
use the "Move" function to create a "live pointer" that
can be moved around on the screen to highlight an
Tip: If using an arrow as a pointer, create the template
with the arrow pointing 'up'. This will make it easier to
rotate the template on the live view, as the rotation
tool's reference point will correspond to the
2. Place templated lines on the live screen to orient a
specimen in a "virtual jig".
3. For repetitive measurements on similar samples,
place templated measurement lines on the screen,
and move them into position.* Then capture the
image with the lines applied upon capture. Any
adjustments to the lines can be quickly made on the
stored image and the measurements sent to a report
in the standard PAX-it manner.
4. Use measurement lines, circles, boxes, etc. as
Go/NoGo indicators on the Live preview.*
5. Place a scale bar on a Live image.*
*Note: Please refer to the PAXcam User Guide section
about setting the template resolution, as it is very
important to make sure that your magnification factor
is correct when using measurements and scale bars.
Image Overlays
4. Go to the 'Advanced' tab of the PAXcam interface, and
use the dropdown list to enter the resolution setting for
the overlays that you will be using. If you have a
standard overlay size, you may leave the checkbox
unchecked and the software will assume all overlays to
be the size specified. If your work requires the use of
differently scaled overlays, you may have the software
prompt for the overlay size each time a different overlay
is used, by checking the checkbox.
NOTE: If your overlay images were not originally captured
with the PAXcam, choose the closest value to the size of
your overlay. Full = 1280 x 1024, Half = 640 x 512, and
Quarter = 320 x 256 pixels. You may find the dimensions
of any stored PAX-it image by right clicking on the image
and choosing "Properties".
5. Press the Image Overlay button. The first
image in the overlay folder will be placed on
the Live preview.
6. On the Advanced tab of the PAXcam
interface, you may use the "Image Transparency" slider to
adjust how much of the live preview is 'bleeding through'
the reference image. Moving the slider towards the left
will make darker areas of your reference image
transparent, so that the Live Preview image may be seen.
Moving the slider towards the right will make lighter
areas of your overlay image transparent, leaving the
darker areas as the overlay component.
Basic sequence for applying an overlay.
1. Capture images to be used as overlays and place
them in a PAX-it folder. Make a mental note of the
resolution of the captured images, as overlays will
need to be scaled to the preview size they will be
used with (see step 4).
‘Image Transparency’ will adjust the
mask properties of the overlay, to
allow the Live Preview image to be
seen behind it.
2. In PAX-it, browse to the folder containing the overlay
images, and right mouse click on the page of
thumbnails to "Set as Overlay Folder".
3. Start the PAXcam and adjust the live preview of the
sample you wish to image.
7. Use the Image Overlay buttons to navigate forward and
backward in your overlay folder, to bring up other
reference images.
8. To remove the template from the preview image, use the
"Remove Template" button. Clicking on either
Image Overlay button will now return you to
the overlay image you were previously on.
Moving the Overlay
The techniques for moving and rotating the image
overlay are exactly the same as for the videotext
template overlays described above. Please refer to
that section for more information.
Uses for the Image Overlay Feature
The primary use for the image overlay is for
comparison of the live image to a reference or
standard for a shape or size estimation. Some
samples do not lend themselves well to automated
image analysis and are best gauged against a
visual reference. For example, gelfoam crosssections do not threshold well for automated sizing
of the foam's internal dimensions. By constructing a
series of reference images, the ranking of a current
unknown sample against the standard reference is
easily accomplished. Similarly, a visual comparison
can be made for grainsize estimation, flake shape
classification, and other similar tests.
When using the image overlays to gauge a live view
against a series of known standards, you can
identify your standard images by placing a videotext
label on the image. If the non-transparent
reference portion of your image is the dark portion,
then make your videotext label with black text, if the
non-transparent portion of your reference image is
the lighter areas then make your videotext label
with white text. NOTE: the label will not appear on
your overlay unless you make it a permanent part
of your image. To do this, go to Image… Burn in
Video Text on the main PAX-it menu after you have
created the label. You may wish to copy your image
first, as burning in labels causes changes to your
image that may not be recovered.
LECO Corporation
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© 2010 LECO Corporation
Metallographic Application Note